title: Lectin-induced regulation of human thymus-independent anti-TNP responses in vitro.
abstract: Recently we showed that human hapten-specific T cell-independent (TI) antibody responses could be elicited in vitro with the antigen trinitrophenylated Brucella abortus (TNP-Ba). Although by definition T cells are not required for TI responses, they have also shown capable of regulating such responses in the mouse. In this study we examine the ability of the T cell lectins Con A and PHA to modulate TI responses of human tonsil cells. Addition of the lectins to cultures on day 0 or day 3 resulted in inhibition (greater than 90%) or enhancement (greater than 150%) of the anti-TNP PFC response, respectively. The inhibition was only apparent if the lectins were added at the onset of culture but not 24 hr later, and was T cell-dependent, because T cell-depleted cultures (less than 0.5% E-rosetting cells) could not be inhibited. The enhancement observed was even greater in T cell-depleted cultures and was antigen-specific because TNP-SRBC but not PC-SRBC targets were lysed and the PFC were inhibited by soluble TNP (greater than 70%). This finding suggested that anti-TNP PFC precursors were proliferating more vigorously or that additional, previously antigen-insensitive cells were being recruited in the presence of lectin.
mesh_terms: D000917:Antibody Formation / Q000187:drug effects*; D001402:B-Lymphocytes / Q000276:immunology*; D002003:Brucella abortus / Q000276:immunology; D002478:Cells, Cultured; D003208:Concanavalin A / Q000494:pharmacology; D006801:Humans; D007700:Kinetics; D008213:Lymphocyte Activation / Q000187:drug effects; D008211:Lymphocyte Cooperation / Q000187:drug effects; D010835:Phytohemagglutinins / Q000494:pharmacology; D014301:Trinitrobenzenes / Q000276:immunology
chemical_list: D010835:Phytohemagglutinins; D014301:Trinitrobenzenes; D003208:Concanavalin A